<html>
    <head>
        <meta http-equiv="X-UA-Compatible" content="IE=9" />
        <link href="style3.css" rel="stylesheet" type="text/css" />
    </head>
    <form method ="post" >
<!--        <input style= "margin-left: 0px; top: 225px; position: relative " name="subscribe" type="submit" value="subscribe" /> -->
    </form>


</html>
<?php
session_start();

//connect to the database
$conn = mysql_connect('localhost', 'root', '') or die(mysql_error());
mysql_select_db('mydb', $conn) or die(mysql_error());
 $member_id = $_SESSION['member_id'];


$result =  mysql_query("SELECT conference_id, long_name FROM conference") Or die(mysql_error());
// save all conferences in array
//$conferences = $_POST['$result'];
if (!mysql_num_rows($result)) { // check if the query returned output or not
          echo  '<script>',
             'alert("There are no conferences");',
             '</script>';
}
//table containing all the conferences available
else {
echo '<table width="100%">
    <tr>
    <td><b>Conference</b>
    </td>
    </tr>';
//redirect to the conference page
//while ($row = mysql_fetch_assoc($result)) {
//    echo//"<tr>
//          //<td><input type=\"checkbox\" name=\"conf[]\" value=\"{$row['conference_id']}\"></td>\n
//	  //<td>{$row['long_name']}</td>
//	  //<td><a href='conferencePage.php?conference_id={$row['conference_id']}'>go to Conference</a </td>
//	  </tr>";
//}

for ($i =0; $i<$row = mysql_fetch_assoc($result); ++$i) {
?>
                        <form method="post" action="">
                <?php
               print "<tr>\n";
                print "<td><input type=\"checkbox\" name=\"conf[]\" value=\"{$row['conference_id']}\"></td>\n";
               echo "<td><width=\"0%\" height=\"0\" style=\"display:none\" value=\"\"</td>\n";
               echo "<td>{$row['long_name']}</td>\n"; // print names
                echo "
	            <td><a href='conferencePage.php?conference_id={$row['conference_id']}'>go to Conference</a </td>";


               }


     if (isset($_POST['subscribe'])) {

                 //an array is created to store all the values of the checkboxes that were clicked
                    $num_conf = $_POST['conf'];
                    //a variable is initialized to store the length of the array as an integer
                    $n = count($num_conf);
                    //loops on all the values in the array
                    for ($i = 0; $i < $n; $i++) {
                        //retrieves the value in the array at position i and stores it in a variable
                        $confid = $num_conf[$i];
                        //check whether this member is subscribed in this conference as a reviewer or not
                    $check_subscriber = mysql_query("SELECT* FROM Member_Privileges
                 WHERE member_id ='$member_id' AND privileges_id ='4' AND conference_id ='$confid'") or die(mysql_error());

                     $row = mysql_fetch_assoc($check_subscriber);
                    //if the rows are greater than one then he is a subscriber  in this conference
                    if ($row > 1) {
                        echo  '<script>',
                          'alert("your are already subscriber in this conference");',
                                  '</script>';
                    }
                    else {
                        //executes a query to insert the values of the ids of the checked conferences into the
                        //table member_privileges with the id of the conference
                        mysql_query("INSERT INTO member_privileges (member_id, privileges_id ,conference_id)
                        VALUES ('$member_id', '4', '$confid')") or die("error");
                         echo  '<script>',
                          'alert("your action done correctly");',
                                  '</script>';

                    }

}
     }

?>
<tr><td><input type="submit" name="subscribe" value="subscribe"></td></tr>
                 <br>
                 <?



}


?>
